Telecommunications apparatus and methods for paging of a mobile device

ABSTRACT

A method of communicating data between a radio network infrastructure and a terminal device in a wireless telecommunications network. The method comprises establishing at a radio network infrastructure element there is data available for communication between the radio network infrastructure and the terminal device and transmitting a paging message for the terminal device from the radio network infrastructure element. The paging message comprises an indication of an identifier for the terminal device and an indication of a network allocated resource for use in subsequently communicating the data between the radio network infrastructure element and the terminal device. In response to receiving the paging message the terminal device transmits to the radio network infrastructure element a paging response indicating the terminal device received the paging message, after which the data is communicated between the radio network infrastructure element and the terminal device using the network allocated resource.

BACKGROUND Field

The present disclosure relates to telecommunications apparatus andmethods.

Description of Related Art

The “background” description provided herein is for the purpose ofgenerally presenting the context of the disclosure. Work of thepresently named inventors, to the extent it is described in thisbackground section, as well as aspects of the description which may nototherwise qualify as prior art at the time of filing, are neitherexpressly or impliedly admitted as prior art against the presentinvention.

Third and fourth generation mobile telecommunication systems, such asthose based on the 3GPP defined UMTS and Long Term Evolution (LTE)architecture are able to support more sophisticated services than simplevoice and messaging services offered by previous generations of mobiletelecommunication systems. For example, with the improved radiointerface and enhanced data rates provided by LTE systems, a user isable to enjoy high data rate applications such as mobile video streamingand mobile video conferencing that would previously only have beenavailable via a fixed line data connection. The demand to deploy thirdand fourth generation networks is therefore strong and the coverage areaof these networks, i.e. geographic locations where access to thenetworks is possible, is expected to increase rapidly.

There is expected to be an increasing need for future wirelesscommunications networks to efficiently support communications with awider range of devices associated with a wider range of data trafficprofiles and types than current systems are optimised to support. Forexample it is expected future wireless communications networks will beexpected to efficiently support communications with devices includingreduced complexity devices, machine type communication devices, highresolution video displays, virtual reality headsets and so on. Some ofthese different types of devices may be deployed in very large numbers,for example low complexity devices for supporting the “The Internet ofThings”, and may typically be associated with the transmissions ofrelatively small amounts of data with relatively high latency tolerance,whereas other types of device, for example supporting high-definitionvideo streaming, may be associated with transmissions of relativelylarge amounts of data with relatively low latency tolerance.

In view of this there is expected to be a desire for future wirelesscommunications networks, for example those which may be referred to as5G or new radio (NR) system/new radio access technology (RAT) systems,as well as future iterations/releases of existing systems, toefficiently support connectivity for a wide range of devices associatedwith different applications and different characteristic data trafficprofiles.

Example use cases currently considered to be of interest for nextgeneration wireless communication systems include so-called EnhancedMobile Broadband (eMBB) and Ultra Reliable and Low LatencyCommunications (URLLC). See, for example, the 3GPP document RP-160671,“New SID Proposal: Study on New Radio Access Technology,” NTT DOCOMO,RAN #71 [1].

The desire to efficiently support transmissions for different serviceswith different characteristics in a wireless telecommunications systemgives rise to new challenges to be addressed to help optimise theoperation of wireless telecommunications systems.

SUMMARY

The present disclosure can help address or mitigate at least some of theissues discussed above.

Respective aspects and features of the present disclosure are defined inthe appended claims.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary, but are notrestrictive, of the present technology. The described embodiments,together with further advantages, will be best understood by referenceto the following detailed description taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the disclosure and many of the attendantadvantages thereof will be readily obtained as the same becomes betterunderstood by reference to the following detailed description whenconsidered in connection with the accompanying drawings wherein likereference numerals designate identical or corresponding parts throughoutthe several views, and wherein:

FIG. 1 schematically represents some aspects of a LTE-type wirelesstelecommunication network which may be configured to operate inaccordance with certain embodiments of the present disclosure;

FIG. 2 schematically represents some aspects of a paging procedure in awireless telecommunications network;

FIG. 3 schematically represents some aspects of a new radio accesstechnology (RAT) wireless telecommunications network which may beconfigured to operate in accordance with certain embodiments of thepresent disclosure;

FIG. 4 schematically represents some further aspects of the wirelesstelecommunication network of FIG. 1; and

FIGS. 5 and 6 are ladder diagrams schematically representing operatingaspects of network infrastructure equipment and a terminal device inaccordance with certain embodiments of the disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1 provides a schematic diagram illustrating some basicfunctionality of a mobile telecommunications network/system 100operating generally in accordance with LTE principles, but which mayalso support other radio access technologies, and which may implementembodiments of the disclosure as described herein. Various elements ofFIG. 1 and certain aspects of their respective modes of operation arewell-known and defined in the relevant standards administered by the3GPP® body, and also described in many books on the subject, forexample, Holma H. and Toskala A [2]. It will be appreciated thatoperational aspects of the telecommunications networks discussed hereinwhich are not specifically described (for example in relation tospecific communication protocols and physical channels for communicatingbetween different elements) may be implemented in accordance with anyknown techniques, for example according to the relevant standards andknown proposed modifications and additions to the relevant standards.

The network includes a plurality of base stations 101A, B, C connectedto a core network 102. Each base station provides a coverage area 103A,B, C (i.e. a communication cell) within which data can be communicatedto and from various terminal devices 104. In accordance withconventional terminology, a terminal device may also be referred to as amobile station, user equipment (UE), user terminal, mobile radio, and soforth. Similarly, a base stations may also be referred to as atransceiver station/nodeB/e-NodeB, eNB, gNB, and so forth. Furthermore,it will be appreciated the terms base station and cell may alsosometimes be used interchangeably, for example, the process of aterminal device connecting to the radio access part of a wirelesstelecommunications system might be referred to as accessing a cell oraccessing a base station. Nonetheless, it will be appreciated in somecases the physical apparatus comprising a base station may compriseequipment for supporting more than one communication cell and in suchcases it can still be appropriate to draw a distinction between basestations and cells.

In terms of basic operation, data are transmitted between base stations101A, B, C and terminal devices 104 using various radio downlink anduplink channels. The core network 102 routes data to and from terminaldevices 104 via respective base stations 101A, B, C and providesfunctions such as authentication, mobility management, charging and soon. To this end, the core network (CN) 102 comprises a mobilitymanagement entity (MME) 105 and a serving gateway (S-GW) entity and apacket data network gateway (P-GW) entity. For simplicity the servinggateway entity and packet data network gateway are schematicallyrepresented in FIG. 1 as a single combined (S-GW/P-GW) gateway entity106.

It is known for a group of base stations (with associated cells) to belogically grouped together into a so-called tracking area (TA). In FIG.1 the communication cells 103A and 103B associated with base stations101A and 101B are schematically represented as belonging to a trackingarea 107. For this particular example it is assumed the communicationcell 103C associated with base station 101C belongs to a differenttracking area, although this other tracking area is not represented inthe figure. The sizes of tracking areas are typically not specified inwireless telecommunications system specifications. However, a typicaltracking area in an LTE-based network might be expected to includeperhaps twenty base stations/cells, but could be more/fewer according tothe implementation at hand. Tracking areas play a role in paging.

As is well understood, various wireless telecommunications networks,such as the LTE-based network represented in FIG. 1, support differentRadio Resource Control (RRC) modes for terminal devices, typicallyincluding: (i) RRC idle mode (RRC_IDLE); and (ii) RRC connected mode(RRC_CONNECTED). When a terminal device transmits data, RRC connectedmode is generally used. The RRC idle mode, on the other hand, is forterminal devices which are registered to the network (EMM-REGISTERED),but not currently in active communication (ECM-IDLE).

For a terminal device in RRC idle mode the core network (CN) 102 isaware that the terminal device is present within the network, but theradio access network (RAN) part (comprising the base stations 101A, B,C) is not. More specifically, for a terminal device in RRC idle mode,core network nodes such as the MME 105 of FIG. 1 recognize the idle modeterminal device at a tracking area level. That is to say, the corenetwork 102 does not attempt to keep track of terminal device locationsat the level of individual communication cells/base stations, but seeksonly to keep track of which tracking area the terminal device iscurrently located within. The core network will generally assume aterminal device is located within the tracking area(s) associated withthe base station most recently accessed by the terminal device, unlessthe terminal device has since provided a specific tracking area update(TAU) to the network. (As is conventional, idle mode terminal devicesare typically required to send a TAU when they detect they have entereda different tracking area to allow the core network to keep track oftheir location.)

Because the core network tracks terminal devices at a tracking arealevel, it is generally not possible for the network infrastructure toknow which specific base station to use when seeking to initiate contactwith a terminal device in idle mode, and this has consequences for howpaging procedures in wireless telecommunication systems are performed.

FIG. 2 is a signaling ladder diagram representing some principles of aconventional core-network level paging procedure for a terminal device104 in an RRC Idle mode in the LTE-type network schematicallyrepresented in FIG. 1. FIG. 2 schematically represents signaling andoperating functions associated with the terminal device 104, the basestations 101A, 101B comprising the tracking area 107, and the MME 105and gateway 106 of the core network 102.

For the sake of this example it is assumed the terminal device 104initially attaches to the network through base station 101A within thetracking area 107 before entering an idle mode. Furthermore, it isassumed the terminal device 104 has not moved to a different trackingarea and so has not provided any tracking area update. Thus, the corenetwork 102 will assume the terminal device is located somewhere withintracking area 107 (i.e. somewhere within the coverage areas ofcommunication cells 103A and 103B which comprise the tracking area 107).

Thus, referring to FIG. 2, in step S1 the terminal device 104 is poweredon.

In step S2 (comprising sub-steps S2 a, S2 b and S2 c), and in accordancewith conventional techniques, an RRC connection procedure (in thisexample an initial attach procedure) is initiated by the terminal devicewith signaling exchanged between the terminal device 104, the basestation 101A, the MME 105, and gateway 106 as schematically representedin the figure. For LTE this signaling comprises RRC connection setupsignaling from the terminal device 104 to the base station 101A (step S2a), attach request signaling from the base station 101A to the MME 105(step S2 b), and GPRS tunnel protocol session request signaling (step S2c).

As is well known, the specific base station through which the terminaldevice initially attaches may be determined from reference signalmeasurements, and so forth, whereby the terminal device determines whichbase station is most appropriate (cell selection).

In step S3 the core network assigns an IP address for the terminaldevice. From this point the core network recognises the existence of theterminal device and keeps track of its location at a tracking area levelas discussed above. Thus, in this particular example, the core networkidentifies the terminal device as being within tracking area 107(because the terminal device has accessed the network through basestation 101A, which is within tracking area 107).

Although not shown in FIG. 2 in the interests of simplicity, the basestation 101A to which the terminal device 104 sends RRC connection setupsignaling in step S2 and the terminal device 104 will exchange furthersignaling to allow the base station 101A to establish capabilityinformation for the terminal device 104. For example, the base station101A will transmit a UE capability enquiry and the terminal device willrespond with a UE capability information message.

As schematically represented in step S4, the terminal device havingattached to the network and exchanged capability information with thebase station, enters RRC idle mode. As is conventional, the base station101A will discard the UE capability information and other contextinformation associated with the terminal device at this stage.

In step S5 the MME 105 recognises that a paging instance has arisen forthe terminal device 104. The specific reason for the paging requirementis not significant, and may, for example be because a third party isseeking to place a telephone call to the terminal device 104.

As has been discussed above, the MME 105 in the core network 102 canrecognise the terminal device is located in one of the communicationcells 103A and 103B which comprise tracking area 107, but the MME 105does not know which one. Accordingly, the MME 105 sends a paging requestmessage over the S1-AP interface to each of the base stations associatedwith the tracking area 107. Thus, in this example the MME 105 sendspaging request messages to both base stations 101A and 101B, asschematically represented in steps S6 and S7. The MME 105 does not senda paging request message to the base station 101C serving communicationcell 103C because communication cell 103C is not within tracking area107 in which the terminal device is taken as being located.

The base stations receiving a paging request message from the MME 105,in this case base stations 101A and 101B, are configured to transmitpaging signaling to seek to establish contact with the terminal device104. This is schematically represented in FIG. 2 in steps S8 and S9.

It is assumed for this example the terminal device has remained withinthe coverage area 103A of base station 101A and so receives the pagingsignaling transmitted in step S9 by base station 101A, and respondsaccordingly, as schematically indicated in step S10, for example byinitiating a random access procedure to establish an RRC connection tothe network. The paging signaling sent in step S8 by base station 101Bis not received by the terminal device 104 and so is in effect wastedsignaling.

Following step S10, the various elements represented in FIG. 2 maycontinue to exchange signaling in accordance with conventionaltechniques, for example depending on why the paging instance arose instep S5.

Thus, FIG. 2 schematically represents a conventional manner for pagingterminal devices in RRC idle mode in a wireless telecommunicationssystem in what might be referred to as core network level paging.

Idle mode terminal devices are conventionally configured to seek pagingmessages periodically. For terminal devices operating in a discontinuousreception (DRX) mode this occurs each time they wake up for their DRXactive time. Paging signals for a specific terminal device aretransmitted in defined frames (Paging Frames)/sub-frames (PagingOccasions) which are derived from the International Mobile SubscriberIdentifier (IMSI) of the terminal device, as well as paging related DRXparameters established in system information transmitted within thenetwork.

In a conventional LTE-based system, a terminal device thus receives andchecks the contents of specific sub-frames (paging occasions) inspecific frames (paging frames) to look for paging signaling. Forexample, in accordance with the standards set out in ETSI TS 136 321V13.0.0 (2016 February)/3GPP TS 36.321 version 13.0.0 Release 13 [3], aPaging Frame (PF) is a downlink radio frame which may contain one ormore Paging Occasion(s) (PO), where a Paging Occasion is a sub-frame inwhich there may be paging signaling. Paging signaling is conveyed on aphysical downlink shared channel (PDSCH) on resources identified from anallocation message addressed to a paging radio network temporaryidentifier (P-RNTI) and conveyed on a physical downlink control channel(PDCCH). P-RNTI is a common identifier for all terminal devices (e.g.set at FFFE in hexa-decimal for the standard defined by ETSI TS 136 321V13.0.0 (2016 February)/3GPP TS 36.321 version 13.0.0 Release 13 [3]).All terminal devices check whether PDCCH at the specific PF/PO includesP-RNTI or not. If there is a PDSCH allocation addressed to P-RNTI in therelevant subframe, the terminal device proceeds to seek to receive anddecode the paging messages transmitted on the allocated resources onPDSCH. The UE then checks the list of IDs contained in the paging recordlist in the received paging message, to determine whether the listcontains an ID corresponding to itself (for example P-TMSI or IMSI), andif so initiates a paging response.

Although the above description has summarised existing LTE pagingprocedures, it is expected that some broadly similar principles may beadopted for future wireless telecommunications networks, and theinventors have recognised there are ways in which these procedures maybe modified to provide enhanced functionality, both for existingwireless telecommunication network architectures and wirelesstelecommunications network architectures based on newer radio accesstechnologies (RATs), such as 5G networks.

FIG. 3 is a schematic diagram illustrating an example networkarchitecture for a new RAT wireless mobile telecommunicationsnetwork/system 300 based on previously proposed approaches which mayalso be adapted to provide functionality in accordance with embodimentsof the disclosure described herein. The new RAT network 300 representedin FIG. 3 comprises a first communication cell 301 and a secondcommunication cell 302. Each communication cell 301, 302, comprises acontrolling node (centralised unit) 321, 322 in communication with acore network component 310 over a respective wired or wireless link 351,352. The respective controlling nodes 321, 322 are also each incommunication with a plurality of distributed units (radio accessnodes/remote transmission and reception points (TRPs)) 311, 312 in theirrespective cells. Again, these communications may be over respectivewired or wireless links. The distributed units 311, 312 are responsiblefor providing the radio access interface for terminal devices connectedto the network. Each distributed unit 311, 312 has a coverage area(radio access footprint) 341, 342 which together define the coverage ofthe respective communication cells 301, 302.

In terms of broad top-level functionality, the core network component310 of the new RAT telecommunications system represented in FIG. 3 maybe broadly considered to correspond with the core network 102represented in FIG. 1, and the respective controlling nodes 321, 322 andtheir associated distributed units/TRPs 311, 312 may be broadlyconsidered to provide functionality corresponding to base stations ofFIG. 1. The term network infrastructure equipment/element may be used toencompass these elements and more conventional base station typeelements of wireless telecommunications systems. Depending on theapplication at hand the responsibility for scheduling transmissions onthe radio interface between the respective distributed units and theterminal devices may lie with the controlling node/centralised unitand/or the distributed units/TRPs.

A terminal device 400 is represented in FIG. 3 within the coverage areaof the first communication cell 301. This terminal device 400 may thusexchange signaling with the first controlling node 321 in the firstcommunication cell via one of the distributed units 311 associated withthe first communication cell 301. In some cases communications for agiven terminal device are routed through only one of the distributedunits, but it will be appreciated in some other implementationscommunications associated with a given terminal device may be routedthrough more than one distributed unit, for example in a soft handoverscenario and other scenarios. The particular distributed unit(s) throughwhich a terminal device is currently connected through to the associatedcontrolling node may be referred to as active distributed units for theterminal device. The active subset of distributed units for a terminaldevice may comprise one or more than one distributed unit (TRP). Thecontrolling node 321 is responsible for determining which of thedistributed units 311 spanning the first communication cell 301 isresponsible for radio communications with the terminal device 400 at anygiven time (i.e. which of the distributed units are currently activedistributed units for the terminal device). Typically this will be basedon measurements of radio channel conditions between the terminal device400 and respective ones of the distributed units 311. In this regard, itwill be appreciated the subset of the distributed units in a cell whichare currently active for a terminal device will depend, at least inpart, on the location of the terminal device within the cell (since thiscontributes significantly to the radio channel conditions that existbetween the terminal device and respective ones of the distributedunits).

In the example of FIG. 3, two communication cells 301, 302 and oneterminal device 400 are shown for simplicity, but it will of course beappreciated that in practice the system may comprise a larger number ofcommunication cells (each supported by a respective controlling node andplurality of distributed units) serving a larger number of terminaldevices.

It will further be appreciated that FIG. 3 represents merely one exampleof a proposed architecture for a new RAT telecommunications system inwhich approaches in accordance with the principles described herein maybe adopted, and the functionality disclosed herein may also be appliedin respect of wireless telecommunications systems having differentarchitectures. That is to say, the specific wireless telecommunicationsarchitecture for a wireless telecommunications system adapted toimplement functionality in accordance with the principles describedherein is not significant to the principles underlying the describedapproaches.

Certain embodiments of the invention as discussed herein may beimplemented in wireless telecommunication systems/networks according tovarious different architectures, such as the example architectures shownin FIGS. 1 and 3 or in other architectures that may be adopted. It willthus be appreciated the specific wireless telecommunicationsarchitecture in any given implementation is not of primary significanceto the principles described herein. In this regard, certain embodimentsof the disclosure may be described generally in the context of a radionetwork infrastructure element communicating with a terminal device,wherein the specific nature of the radio network infrastructure elementand the terminal device will depend on the network infrastructurearchitecture for the implementation at hand. For example, in somescenarios the radio network infrastructure element may comprise a basestation, such as an LTE-type base station 101 as shown in FIG. 1 whichis adapted to provide functionality in accordance with the principlesdescribed herein, and in other examples the network infrastructureequipment may comprise a controlling node 321, 322 and/or a TRP 311, 312of the kind shown in FIG. 3 which is adapted to provide functionality inaccordance with the principles described herein. For the sake ofsimplicity the term base station may be used herein to refer to any formof radio network infrastructure element configured to providefunctionality in accordance with the principles described herein.

As already noted above, it is well understood that in wirelesstelecommunications networks, such as an LTE type network, there aredifferent Radio Resource Control (RRC) modes for terminal devices. Forexample, it is common to support an RRC idle mode (RRC_IDLE); and an RRCconnected mode (RRC_CONNECTED).

Generally speaking, in RRC connected mode a terminal device is connectedto a base station in the sense of being able to receive user plane datafrom the base station and in RRC idle mode the terminal device is notconnected to a base station in the sense of not being able to receiveuser plane data from the base station. In idle mode the terminal devicemay still receive some communications from base stations, for examplereference signaling for cell reselection purposes and other broadcastsignaling. The RRC connection setup procedure of going from RRC idlemode to RRC connected mode may be referred to as connecting to acell/base station.

One characteristic of the RRC connected mode is the allocation of acell-specific radio network temporary identifier (C-RNTI) to theterminal device to allow the base station to which the terminal deviceis connected to address communications to the terminal device. Aterminal device in a conventional RRC idle mode will not be associatedwith this kind of RNTI.

Another characteristic of the RRC connected mode is the association ofone or more dedicated logical channels with the terminal device to allowthe terminal device to exchange data with the base station to which itis connected. A terminal device in a conventional RRC idle mode will notbe associated with this kind of dedicated logical communication channel.

Another characteristic of the RRC connected mode is that a terminaldevice in RRC connected mode will have established a security context byexchanging security settings with the base station to which it isattached as part of its RRC connection procedure. A terminal device in aconventional RRC idle mode will not, however, have this kind ofestablished security context.

More generally, a base station to which a terminal device is connectedin RRC connected mode will retain information relating to the terminaldevice, for example its allocated C-RNTI, logical channel configurationsettings, security settings, and so on, to allow the base station tocommunicate with the terminal device. This information may generally bereferred to as a terminal device context in/at the base station (orother network infrastructure equipment/node according to the specificnetwork architecture at hand).

In accordance with conventional approaches, when a terminal devicereleases its RRC connection with respect to a particular base stationand transitions to conventional RRC idle mode, the base station releasesthe terminal device context.

Whilst in RRC idle mode a terminal device will receive signaling frombase stations covering its location (i.e. base stations within radiosignaling range of its location), for example reference signaling andother broadcast signaling. Based on this signaling the terminal deviceis able to determine what is currently the most appropriate base stationto connect to were the terminal device required to establish aconnection to the network, for example to transmit uplink data or inresponse to a paging request. This ongoing procedure/process fordetermining the most appropriate base station to connect to is known ascell selection/reselection. The terminal device will synchronise to aselected base station and decode relevant broadcast information, forexample information transmitted in master information block (MIB) andsystem information block (SIB) transmissions, from the selected basestation so the terminal device is able to initiate a radio resourceconnection with the selected base station as and when appropriate. Aterminal device will also monitor a paging channel associated with thebase station to which it is synchronised in idle mode to identify if anypaging requests are addressed to the terminal device. When a terminaldevice operating in an RRC idle mode wishes to transition to an RRCconnected mode to exchange data with the network, it transmits an RRCconnection request message to the currently selected base station toinitiate an RRC connection procedure in accordance with well-establishedtechniques.

In association with the RRC connection procedure, signaling is exchangedbetween the terminal device and the base station to allow the basestation to establish a context for the terminal device to supportsubsequent communications in the RRC connected mode, for example toexchange information relating to a C-RNTI for the terminal device,dedicated logical channel configuration settings, and security settings.

Thus to summarise some aspects of RRC idle and connected modes/states,In RRC Connected State, the network is aware of the UE's location at thecell level and has the UE context thereby allowing scheduling ofphysical resources for user data transmissions because the UE (terminaldevice) has been assigned a temporary ID (C-RNTI) which is unique tothat UE within the cell and hence the UE can be directly addressed bythe network. In the Idle Mode, the network is aware of the UE's locationwithin a Tracking Area and does not have the UE context and cannotschedule physical resources for user data transmission because the UEdoes not have a unique identifier within a cell (C-RNTI). The UE movesfrom an Idle Mode to an RRC Connected State by establishing an RRCConnection which assigns a C-RNTI using a random access (RACH)procedure. The UE moves from RRC Connected State to Idle Mode byreleasing its RRC Connection (and hence releasing C-RNTI). In idle mode,a UE is addressed by first paging the cells within the tracking area.The UE monitors for P-RNTI (paging identifier) on PDCCH rather thanC-RNTI as it does in RRC connected state. The paging message which isreceived following P-RNTI detection contains the UE identity, and if theUE receives this it will then respond by establishing an RRC connectionand having a C-RNTI assigned.

The use of RRC idle mode can be beneficial for a terminal device, forexample in terms of power saving. However, a drawback of switching toRRC idle is the signaling overhead associated with establishing a newRRC connection when the terminal device is required to reconnect to abase station and exchange data with the base station to allow the basestation to establish a context for the terminal device. This signalingoverhead has an impact for the terminal device in terms of using powerand also for the wireless telecommunications network as a whole in termsof taking up radio resources that might otherwise be used for othercommunications. Consequently, there is typically a compromise to be madebetween entering RRC idle mode frequently (to preserve terminal devicepower) and remaining in RRC connected mode for longer periods (to reducere-connection signaling overhead).

This means that while RRC idle and RRC connected states can helpefficiently support communications in scenarios involving thetransmission of relatively large amounts of data, it has been recognisedthat these states may be less efficient in supporting communications inscenarios in which relatively small amounts of data are transmitted,potentially relatively frequently, for example in accordance with someof the new types of traffic profiles that may be expected to become moreprevalent in new telecommunication systems.

With this in mind it has been proposed for Release 14 of the 3GPPstandard to consider using a modified approach for RRC modes/states tosupport certain communications. See, for example, the 3GPP document “NewWI proposal: Signaling reduction to enable light connection for LTE”,3GPP TSG RAN Meeting #71, RP-160540, Gothenburg, Sweden, 7-10 Mar. 2016[4].

One proposal is to define a new/modified RRC mode in which the a UE isnot in an active RRC connected mode with the radio access network (RAN),but is considered to be RRC Connected from a CN (core network) point ofview, so that data can be sent without CN-level paging, but with pagingperformed instead at the RAN level, to cause/trigger the UE to resumeRRC connection (enter an RRC connected mode). This modified RRC statemay be referred to as an “RRC connected inactive” state and may havecharacteristics as discussed in the 3GPP document “Text Proposal to TR38.804 on UE states and state transitions for NR”, 3GPP TSG-RAN WG2 #96,R2-168856, R2-168856, 14-18 Nov. 2016 [5]. This approach has the benefitof being able to allow the UE to enter a more power efficient state,while reducing the signaling between the CN and the RAN. The overallprocedure allows RAN to take over responsibility for paging the UE,effectively hiding the RRC state transitions and mobility from the CN,and the CN therefore may directly send data as if the UE was stillconnected and in the same cell.

Much like conventional paging procedures at the CN level (e.g. asdiscussed above with reference to FIG. 2), paging procedures at the RANlevel may be associated with a RAN notification area corresponding tothe CN tracking area concept. That is to say, the base stations (orother TRPs) supporting the RAN in a network may be notionally dividedinto groups of base stations comprising respective RAN notificationareas. A terminal device leaving a RAN paging notification area may beconfigured to inform/update the network of it changing location in muchthe same way as a terminal device leaving a conventional tracking areatransmits a tracking area update. For ease of explanation it is assumedfor the example discussed here that the RAN notification areascorrespond with the CN level tracking areas of the network, and in thatsense the terminology notification area and tracking area may be usedinterchangeably. However, it will be appreciated there is no need forthe RAN level notification areas/tracking areas to correspond in sizeand arrangement with the CN level tracking areas, and in fact it mayexpected in practice that the RAN level notification areas willtypically be smaller (i.e. comprise fewer base stations) than the CNlevel paging areas (i.e. what are referred to as tracking areas in LTEterminology), and further more may be terminal device specific. However,the relative sizes of, and the degree of correspondence between, the RANlevel notification areas and the CN level paging areas is notsignificant to the principles described herein.

Thus, from the RAN point of view, an “anchor” eNB (e.g. the last eNB theUE was connected to) may be defined, which stores the UE contextinformation. When the CN attempts to transmit data to the UE, the RANthen attempts to page the UE on the anchor eNB, and if there is noresponse, the paging may then be performed on all of the cells in thetracking area/RAN notification area, in order to locate the UE. Asummary of this approach may be found in the 3GPP document “Evaluationon RAN initiated paging and MME initiated paging”, 3GPP TSG-RAN WG2Meeting #94, R2-163930, Nanjing, China, 23-27 May 2016 [6]. It will beappreciated there are various aspects of the specific paging procedurethat may be adopted, for example in terms of whether the anchor basestation should instruct other base stations in the RANtracking/notification area to attempt to page the terminal device at thesame time as the anchor base station pages the terminal device or onlyafter failing to successfully page the terminal device, that will dependon the implementation at hand, and are not significant here.

The overall procedure in the RAN part of the network, from a terminaldevice's point of view, may be similar to the suspend/resume procedureintroduced in Release 13 of the 3GPP standards for “Internet of Things”terminal devices. Thus when a terminal device connection to a basestation is released, a “resume ID” is assigned to context informationstored in the network for the terminal device, and when the terminaldevice reconnects using the “resume” procedure, the resume ID is used tolocate the stored context information for the terminal device in thenetwork.

Recent discussions within the 3GPP community have further consideredissues of notification/tracking in a RRC connected inactive state for 5Gnew Radio (NR or 5G-RAN), for example as set out in the 3GPP documents“RAN based Update mechanism for new RAN state”, 3GPP TSG RAN WG2 Meeting#96, R2-168525, Reno, USA, 14-18 Nov. 2016 [7]; “Discussion on RANnotification area for the new RRC state” 3GPP TSG RAN WG2 Meeting #96,R2-168524, Reno, USA, 14-18 Nov. 2016 [8]; and “Inactive Stateprinciples—RAN based notification area”, 3GPP TSG RAN WG2 Meeting #96,R2-168602, Reno, USA, 14-18 Nov. 2016 [9]. Based on these discussionsvarious aspects relating to using this type of approach have beendiscussed, such as:

-   -   RAN2 should assume that UEs perform CN level location updates        when crossing a TA boundary when in RRC connected inactive mode        (in addition to RAN updates based on RAN notification areas).    -   There will be NG Core/CN Location Area code (similar to Tracking        Area code) broadcast in system information of an NR Cell.    -   RAN based notification area is UE-specific and configurable by        the base station via dedicated signaling.    -   There will be a unique global Cell ID broadcast in system        information of NR Cell.    -   For the RRC connected inactive state there will be a way to        configure the UE with a RAN based notification area that is        smaller than a TA.    -   A RAN notification area may cover a single cell or multiple        cells.

Certain embodiments of the disclosure are directed towards methods andapparatus for efficiently communicating data, in particular relativelysmall amounts of downlink data, with terminal devices which are not inan RRC connected mode, for example terminal devices which may be in anRRC idle mode or an RRC connected inactive mode. In accordance withcertain examples, this may be achieved by communicating data withterminal devices in association with modified paging procedures asdiscussed further herein.

FIG. 4 schematically shows some further details of thetelecommunications system 100 shown in FIG. 1 according to an embodimentof the present disclosure. As already noted, the telecommunicationssystem 100 in this example is based broadly around an LTE-typearchitecture, but the telecommunications system may also support otherradio access technologies, either using the same hardware as representedin FIG. 4 with appropriately configured functionality, or separatehardware configured to operate in association with the hardwarerepresented in FIG. 4. Many aspects of the operation of thetelecommunications system/network 100 are known and understood and arenot described here in detail in the interest of brevity. Operationalaspects of the telecommunications system 100 which are not specificallydescribed herein may be implemented in accordance with any knowntechniques, for example according to the current LTE-standards and otherproposals for operating wireless telecommunications systems.

The telecommunications system 100 comprises a core network part (evolvedpacket core) 102 coupled to a radio network part. The radio network partcomprises a base station (evolved-nodeB) 101A coupled to a terminaldevice 104. In this example representation in FIG. 4, only one basestation 101A and one terminal device 104 are represented. However, itwill of course be appreciated that in practice, and as schematicallyrepresented in FIG. 1, the radio network part will typically comprise aplurality of base stations serving a larger number of terminal devicesacross various communication cells. The network may also potentiallyinclude transceiver stations supporting radio communications withterminal devices on cells operating in accordance with other radioaccess technologies, such as UTRAN, GERAN, WLAN or a 5G new RAT.However, only a single base station and terminal device are shown inFIG. 4 in the interests of simplicity.

The terminal device 104 is arranged to communicate data to and from thebase station (transceiver station) 101A. The base station is in turncommunicatively connected to the serving gateway, S-GW, (not shown inFIG. 4) in the core network part which is arranged to perform routingand management of mobile communications services to the terminal devicein the telecommunications system 100 via the base station 101A. In orderto maintain mobility management and connectivity, the core network part102 also includes the mobility management entity, MME, (not shown inFIG. 4) which manages the enhanced packet service, EPS, connections withthe terminal device 104 operating in the communications system based onsubscriber information stored in a home subscriber server, HSS. Othernetwork components in the core network (also not shown for simplicity)include a policy charging and resource function, PCRF, and a packet datanetwork gateway, PDN-GW, which provides a connection from the corenetwork part 102 to an external packet data network, for example theInternet. As noted above, the operation of the various elements of thecommunications system 100 shown in FIG. 4 may be conventional apart fromwhere modified to provide functionality in accordance with embodimentsof the present disclosure as discussed herein. It will be appreciatedembodiments of the invention may in general be implemented in wirelesscommunications systems operating in accordance with different radioaccess technologies, for example, one or more of UTRAN, GERAN, WLAN or a5G new RAT (NR) networks, and these other radio access technologies willnot necessarily incorporate the same network infrastructure componentsas for an LTE implementation (e.g. there may be no serving gateway innew RAT networks).

The terminal device 104 is adapted to support operations in accordancewith embodiments of the present disclosure when communicating with thebase station 101A as discussed further herein. The terminal device 104comprises transceiver circuitry 112 (which may also be referred to as atransceiver/transceiver unit) for transmission and reception of wirelesssignals and processor circuitry 113 (which may also be referred to as aprocessor/processor unit) configured to control the terminal device 104.The processor circuitry 113 may comprise various sub-units/sub-circuitsfor providing functionality in accordance with embodiments of thepresent disclosure as described herein. These sub-units may beimplemented as discrete hardware elements or as appropriately configuredfunctions of the processor circuitry. Thus the processor circuitry 113may comprise circuitry which is suitably configured/programmed toprovide the desired functionality described herein using conventionalprogramming/configuration techniques for equipment in wirelesstelecommunications systems. The transceiver circuitry 112 and theprocessor circuitry 113 are schematically shown in FIG. 4 as separateelements for ease of representation. However, it will be appreciatedthat the functionality of these circuitry elements can be provided invarious different ways, for example using one or more suitablyprogrammed programmable computer(s), or one or more suitably configuredapplication-specific integrated circuit(s)/circuitry/chip(s)/chipset(s).It will be appreciated the terminal device 104 will in general comprisevarious other elements associated with its operating functionality, forexample a power source, user interface, and so forth, but these are notshown in FIG. 4 in the interests of simplicity.

The base station 101A comprises transceiver circuitry 110 (which mayalso be referred to as a transceiver/transceiver unit) for transmissionand reception of wireless signals and processor circuitry 111 (which mayalso be referred to as a processor/processor unit) configured to controlthe base station 101A to operate in accordance with embodiments of thepresent disclosure as described herein. The processor circuitry 111 mayagain comprise various sub-units, such as a scheduling unit, forproviding functionality in accordance with embodiments of the presentdisclosure as explained further below. These sub-units may beimplemented as discrete hardware elements or as appropriately configuredfunctions of the processor circuitry. Thus, the processor circuitry 111may comprise circuitry which is suitably configured/programmed toprovide the desired functionality described herein using conventionalprogramming/configuration techniques for equipment in wirelesstelecommunications systems. The transceiver circuitry 110 and theprocessor circuitry 111 are schematically shown in FIG. 4 as separateelements for ease of representation. However, it will be appreciatedthat the functionality of these circuitry elements can be provided invarious different ways, for example using one or more suitablyprogrammed programmable computer(s), or one or more suitably configuredapplication-specific integrated circuit(s)/circuitry/chip(s)/chipset(s).It will be appreciated the base station 101A will in general comprisevarious other elements associated with its operating functionality, suchas a scheduler. For example, although not shown in FIG. 4 forsimplicity, the processor circuitry 111 may comprise schedulingcircuitry, that is to say the processor circuitry 111 may beconfigured/programmed to provide the scheduling function for the basestation 101A.

Thus, the base station 101A is configured to communicate data with theterminal device 104 over a radio communication link 109 using theprinciples described herein.

In broad summary, to help facilitate efficient communication of data inwireless telecommunications networks, certain example approaches inaccordance with certain embodiments of the disclosure propose tocommunicate data between a radio network infrastructure element (i.e. anelement of the radio access network infrastructure, such as a basestation or other form of TRP depending in the network infrastructure athand) using a network allocated resource (such as a network allocatedidentifier or network allocated physical transmission resources), thatis allocated to a terminal device in association with a paging messagefor the terminal device.

FIG. 5 is a ladder diagram schematically representing some aspects ofsignaling exchange between the terminal device 104, the base station101A and the core network 102 of FIGS. 1 and 4 in accordance withcertain embodiments of the disclosure.

For the sake of providing a specific example, it is assumed here theterminal device 104 is within the communication cell 103A supported bythe base station 101A and is not in an active RRC connected mode but isin an RRC connected inactive mode of the kind recently proposed anddiscussed above. It is further assumed that prior to entering thenon-active RRC connected mode, the terminal device was in an active RRCconnected mode with respect to the base station 101A, for example,because the terminal device was previously involved in an ongoing datacommunication session with the base station 101A before entering the RRCconnected inactive mode when that data communication session hadfinished. Furthermore still, it is assumed that at the start of theprocessing represented in FIG. 5, data for communication between thebase station and the terminal device has become available in thenetwork, for example because the core network has received the data froman external source for transmission to the terminal device. The data maybe user data (i.e. data associated with a layer higher than the physicallayer), but the specific content of the data and the reason why the datahas become available is not significant to the principles describedherein. It may generally be expected approaches in accordance with theprinciples described herein may be most applicable for relatively smallamounts of data, for example on the order of up to the amount of datathat can be communicated in a single subframe, but the approach can inprinciple be used for communicating any amount of data.

In step T1 of the processing represented in FIG. 5 the core network 102conveys the data intended to be communicated to the terminal device 104to the base station 101A along with an indicator of the terminal devicefor which the data is intended, and this may be done in accordance withconventional techniques. In accordance with the principles discussedabove, the transition of the UE 104 to the RRC connected inactive modeprior to the processing represented in FIG. 5 may be transparent to thecore network 102. Accordingly, in step T1 the core network simplycommunicates the data to the base station 101A with which the terminaldevice 104 was last in active RRC connected mode in the same way as ifthe terminal device was in fact still in an active RRC connected mode onthat base station (which so far as the core network is concerned in thisexample, it still is). In this regard the base station 101A may bereferred to as an anchor base station/anchor eNB for the terminaldevice. Receiving the data from the core network in step T1 causes thebase station to establish there is data available for communicationbetween the base station and the terminal device. It will be appreciatedthis example in which the base station 101A receives the data forcommunication to the terminal device from the core network representsonly one example implementation scenario. In other implementationscenarios the base station may receive the data for communication to theterminal device from another source, for example from another basestation/eNB.

The base station 101A is aware the terminal device 104 is in an RRCconnected inactive mode, but in accordance with the proposed operatingprinciples for the RRC connected inactive mode, the base station is notaware of whether the terminal device is still within its communicationcell or has moved to another communication cell. As noted above, it isassumed in this example the terminal device has remained within thecommunication cell of the base station 101A while in the RRC connectedinactive mode. Nonetheless, because the base station 101A is not awareof this, it undertakes further communications with other base stationswhich are not shown in FIG. 5 in the interests of simplicity, but whichare discussed further below with reference to FIG. 6.

In step T2, having established there is data available for communicationwith the terminal device, the base station (radio network infrastructureelement) 101A transmits a paging message for the terminal device 104that includes an identifier for the terminal device that allows theterminal device to determine it is the intended recipient of the pagingmessage. In this regard, the paging message may be transmitted by thebase station 101A generally in accordance with established techniques,for example corresponding to step S9 of FIG. 2, but in accordance withcertain embodiments of the disclosure, the paging message furtherconveys additional information to the recipient terminal device. Inparticular, in addition to containing an indication of an identifier forthe terminal device, the paging message further comprises an indicationof a network allocated resource that may be used for subsequentlycommunicating the data between the radio network infrastructure elementand the terminal device. In the specific example presented in FIG. 5,the network allocated resource comprises a cell-specific radio networktemporary identifier, C-RNTI, to which a subsequent allocation of radioresources for conveying the data may be addressed. In this example, thepaging message further includes an indication of a preamble to be usedby the terminal device in responding to the paging message. In someexample embodiments, the paging message may further include timingadvance information, resource allocation information, or otherinformation related to the transmission of a response message in theuplink, for example using PUCCH or PUSCH channels in LTE, or equivalentchannels in NR.

Thus, the paging message of step T2 may comprise physical transmissionresource allocation signaling addressed to a common radio networktemporary identifier for paging, P-RNTI, with transmissions on thephysical transmission resources indicated by the allocation signalingcontaining an identifier for the terminal device and an indication ofthe network-allocated resource, which in this example comprises a C-RNTIallocated to the terminal device. The C-RNTI in this example may beselected by the base station from among the available C-RNTI havingregard to the same considerations as when allocating a C-RNTI to aterminal device during a conventional RRC connection procedure, althougha significant difference here is that the terminal device is allocatedthe C-RNTI in the paging message and not as part of an RRC connectionprocedure.

In step T3, on receiving the paging message and determining the pagingmessage is addressed to it (on the basis of the indication of anidentifier for the terminal device included in the paging message), theterminal device transmits a paging response. In a conventional pagingprocedure, a terminal device will respond to a paging message byinitiating a random access procedure to initiate an RRC connection setupprocedure. A first step in the random access procedure is thetransmission of a random access preamble. In accordance with certainembodiments of the disclosure, in step T3 the terminal device transmitsa preamble derived from the indication of the allocated preamblereceived from the base station in step T2 on a random access channel.The transmission of this preamble corresponds with the paging response,and the terminal device does not proceed to complete an RRC connectionset-up procedure. In some alternative embodiments the paging responsemay be transmitted after performing random access (Msg1) and receiving arandom access response (Msg2) including an uplink grant to transmit anRRC message (Msg3).

On receiving the paging response (which may be a preamble or a messageor another indication) transmitted by the terminal device in step T3,the base station 101A is able to recognise from the paging response(e.g. based on the preamble used in this example implementation) thatthe paging response has come from the terminal device to which thepaging message was addressed in step T2 (since it was this pagingmessage that indicated the specific preamble to use for the pagingresponse in this example implementation). Accordingly, reception of therelevant preamble is taken by the base station 101A to be an indicationthat the terminal device 104 received the paging message transmitted instep T2 (i.e. the terminal device is within the coverage cell of thebase station 101A).

Thus, on completion of step T3, the base station 101A has determinedthat the terminal device to which the data received from the corenetwork in step T1 is to be transmitted is within its coverage area, andfurthermore the base station 101A has provided the terminal device withan indication of a network allocated resource, in this example a C-RNTI,that the network can now use to communicate data with the terminaldevice. Significantly, the network allocated resource for supportingsubsequent data exchange is provided to the terminal device without theterminal device needing to enter an active RRC connected mode.

In step T4 the base station 101A proceeds to communicate the datareceived from the core network 102 in step T1 to the terminal device104. In this example implementation this is done by the base stationallocating downlink resources to the terminal device by addressingcontrol signaling on a physical downlink control channel, e.g. PDCCH inLTE terminology, to the C-RNTI allocated to the terminal device in thepaging message of step T2 to indicate physical transmission resources ona physical downlink shared channel, e.g. PDSCH in LTE terminology, onwhich the data is to be transmitted. In this regard, the process oftransmitting the data in step T4 may be based on conventional datatransmission schemes in wireless telecommunications networks, albeitwith the terminal device not being in an active RRC connected state andhaving received its temporary radio network identifier in associationwith a paging message received from the base station (i.e. step T2 inFIG. 5) as opposed to during a random access connection procedure.

Whereas FIG. 5 schematically shows the principles underlying an approachin accordance with certain embodiments of the disclosure in which aterminal device has remained within the coverage area/cell of the basestation 101A to which it was RRC connected before transitioning to theRRC connected inactive mode, in the general case, a terminal device inRRC connected inactive mode may move to the coverage area associatedwith another base station due mobility. If the terminal device remainswithin the same RAN notification area (which in this example ifconsidered for ease of explanation to correspond to (i.e. comprise thesame base stations as) the CN level tracking area 107 shown in FIG. 1),it may be expected the terminal device will not notify the network ofthis mobility. Accordingly, it is possible that when the base station towhich the terminal device was last RRC connected receives data from thecore network, the terminal device might no longer be within its coveragearea, and the base station will not know this. Furthermore, for aterminal device which has transitioned to the proposed RRC connectedinactive mode, the core network will not be aware the radio accessnetwork is unaware of the location of the terminal device, and so itwill not initiate a conventional core network level paging procedure,but will simply forward data to the base station with which the terminaldevice was last active RRC connected mode (e.g. as in step T1 of FIG.5). To address this issue, what might be referred to as radio networklevel paging is adopted as noted above. Put simply, when a base stationreceives data from the core network for a terminal device that it haspreviously configured to enter an RRC connected inactive state, inaddition to seeking to page the terminal device as discussed above withreference to FIG. 5, the base station also triggers other base stationsin the tracking area to seek to page the terminal device in a similarmanner. An approach along these lines is schematically shown in thesignaling ladder diagram of FIG. 6.

Thus, FIG. 6 is a ladder diagram schematically representing some aspectsof signaling exchange between the terminal device 104, the base station101A, the base station 101B, and the core network 102 of FIG. 1 inaccordance with certain embodiments of the disclosure.

For the sake of providing a specific example, it is assumed here theterminal device 104 is located within the communication cell 103Bsupported by the base station 101B and is in an RRC connected inactivemode of the kind recently proposed and discussed above. It is furtherassumed that prior to entering the non-active RRC connected mode, theterminal device was in an active RRC connected mode with respect to thebase station 101A, for example, because the terminal device waspreviously located within the communication cell 103A supported by thebase station 101A and involved in an ongoing data communication sessionwith the base station 101A before being configured to enter the RRCconnected inactive mode by the base station 101A. Thus it is assumed theterminal device 104 has moved from a location within the communicationcell 103A supported by the base station 101A to a location within thecommunication cell 103B supported by the base station 101B while in theRRC connected inactive mode.

By way of terminology, the base station 101A with which the terminaldevice was last in an active RRC connected state may be referred to asthe anchor base station 101A for the terminal device 104, and the basestation 101B supporting the communication cell into which the terminaldevice has moved may be referred to as the target base station 101B, orthe currently selected base station 101B (i.e. the base station theterminal device has currently selected according to its cell(re)selection procedures). The communication cells supported by therespective base stations may be similarly referred to as the anchor cell103A and the target (currently selected) cell 101B.

In this example the anchor base station and the target base station arein the same RAN notification area/tracking area 107, and so the terminaldevice 104 will not have provided any indication to the network that itsmobility has moved it from the anchor cell to the target cell. Rather,the terminal device 104 will simply have reselected a new base stationin accordance with conventional cell selection procedures and startedmonitoring relevant transmissions on that cell, for example the pagingchannel. Furthermore, and as discussed above, in accordance withproposed approaches for the RRC connected inactive mode, the corenetwork 102 in this example will also be unaware the terminal device 104is no longer in an active RRC connected state with respect to the anchorbase station, and so will assume the terminal device remains within theanchor communication cell 103A. Consequently, when data for the terminaldevice is received by the core network, it is forwarded to the anchorbase station in the normal way, and as discussed above with reference tostep T1 in FIG. 5.

Thus, step U1 in FIG. 6 is similar to, and will be understood from, stepT1 in FIG. 5, and in step U1 data is received at the anchor base station101A from the core network 102 (e.g. a 5G/new RAT core network/evolvedpacket core (EPC)).

Because the anchor base station 101A is aware it has configured theterminal device to RRC connected inactive mode, the anchor base stationknows the terminal device may have moved out of its coverage areawithout the anchor base station being aware. Accordingly, in addition toseeking to page the terminal device by transmitting a paging message forthe terminal device corresponding to that discussed above in relation tostep T2 of FIG. 5 (represented in step U3 FIG. 6), the anchor basestation also notifies other base stations in its tracking area that theyshould also seek to page the terminal device, which in this exampleincludes the target base station 101B in whose coverage area theterminal device is now located. Typically a RAN paging tracking area maycomprise more than two base stations, but only two are represented inFIG. 6 in the interests of simplicity.

Thus in step U2 the base station sends signaling to the target basestation (and other base stations in the RAN tracking area (not shown inFIG. 6)) to indicate data has become available in the network for theterminal device 104. In this example implementation it is assumed theanchor base station also transmits the data itself to the target basestation. However, at this stage of the processing the anchor basestation does not know the target base station is the one covering theterminal device's new location, and so, as noted above, will sendcorresponding signaling to all base stations in its tracking area.Accordingly, in some other implementations, for example if it isexpected the amount of data may be relatively large, the anchor basestation might not transmit the data to the target base station at thisstage of the processing to save on the amount of signaling neededbetween base stations, but may instead only transmit an indication thatthere is data available for the terminal device. The data itself maythen be forwarded to the relevant base station later when it isdetermined which base station is covering the terminal device's currentlocation (i.e. which base station is the target base station).

In step U3 the anchor base station transmits a paging message to theterminal device as discussed above with reference to step T2 in FIG. 5.

In step U4, the target base station (and all other base stations in thetracking area which received the notification in step U2), havingestablished there is data available for transmission from the radionetwork infrastructure to the terminal device that might be within theircoverage area, also sends a paging message for the terminal device.These paging messages correspond with the paging message transmitted bythe anchor base station, as discussed above with reference to step T2 inFIG. 5. In some cases the anchor base station may indicate to the otherbase stations in its tracking area, including the target base station,the specific preamble and/or network allocated resource to indicate intheir paging message in the notification of step U2 so that all basestations which transmit a paging message identify the same preambleand/or network allocated resource (in this case C-RNTI). However, inother implementations, the individual base stations may be free to maketheir own selection of the preamble and/or network allocated resource(e.g. C-RNTI) to include in their paging message. This can help retainflexibility in how these parameters are used and allocated within eachcommunication cell. This in accordance with some approaches theallocated network resource (e.g. C-RNTI) may be coordinated across allcells in a tracking area (RAN notification area). In some otherapproaches the allocated network resource (e.g. C-RNTI) may be allocatedby individual base stations on a per-cell basis such that each basestation involved in paging the terminal device allocates a resource forthe terminal device that is reserved for use to support subsequentcommunications with the terminal device, or reserved until it isdetermined the UE is not located in the relevant cell, e.g. thereservation can be lifted if no response to the paging message isreceived within a predetermined period of time or based on signalingreceived form another base station, e.g. signaling indicating anotherbase station will serve the data communication with the terminal device.

As noted above, the paging may be based on broadly conventionaltechniques, but modified to incorporate additional information such asdiscussed above, which in this example includes a C-RNTI which isallocated (i.e. reserved) for the terminal device to support subsequentdata exchange without requiring the terminal device to enter an activeRRC connected mode. Thus, a paging message may be sent by addressing anallocation of physical transmission resources to a common pagingidentifier, e.g. P-RNTI in an LTE context, with data transmitted on theallocated physical transmission including an identifier for the terminaldevice(s) being paged, and in accordance with the principles describedherein, also an indication of a network allocated resource that may beused for subsequently communicating with the terminal device. Theidentifier for a terminal device being paged may, for example, comprisea TMSI (Temporary Mobile Subscriber Identity) or an IMSI (InternationalMobile Subscriber Identity) for the terminal device or a Resume IDallocated to the terminal device before suspension of the RRCconnection/entering the inactive mode.

In step U5 the terminal device transmits a paging response to whicheveris its currently selected base station, i.e. in this example the targetbase station, based on having received the paging message received fromthis base station. This step is similar to, and will be understood fromthe above description of step T3 in FIG. 5, albeit the communication isbetween the terminal device and the target base station based on thepaging message received from the target base station, rather thanbetween the terminal device and the base station with which it was mostrecently in an active RRC connected mode.

On receiving the paging response in step U5, the target base stationdetermines the terminal device 104 is within its coverage area (i.e. itis target base station). In this example implementation, the target basestation has already received the data to be communicated with theterminal device in step U2, and so there is in principle no need toinform the anchor base station that it will communicate the data to theterminal device. However, if the data is not transmitted to all basestations in a RAN tracking area in step U2, the target base station may,on determining it is the base station covering the terminal device'scurrent location, inform the anchor base station of this, and the anchorbase station may then communicate the data to the target base station.All other base stations in the tracking area/RAN notification area(including the anchor base station) do not receive a paging response inresponse to the paging messages they have sent for the terminal device,and so these base stations may determine the terminal device is notwithin their communication cell. These other base stations may thusrelease the reservation of the network allocated resource indicated intheir paging message and discard any data they have received for theterminal device (of course if the anchor base station itself has not yetcommunicated the data to the target base station, it should not discardthe data until it has done so). Although in principle each base stationmay determine it is not responsible for serving the terminal devicebased on it not receiving a response to its paging message, in practiceit may be more appropriate for the base stations to communicate with oneanother to indicate when a base station has received a response to itspaging message. Thus a base station that receives a response to itspaging message may inform other base stations of this, so the other basestations know they are not responsible for serving the terminal device.This can help, for example, ensure an appropriate mechanism forre-paging can be provided, for example if a base station does notreceive a response from the terminal device and does not receive anyindication from another base station indicating the other base stationhas received a response from the terminal device within a predefinedperiod, the base station may attempt to re-page the terminal device.

In a manner corresponding to that described above for step T4 in FIG. 5,and after step U5, in step U6 the target base station 101B proceeds tocommunicate the data received from the core network 102 by the anchorbase station 101A (in steps U1 and U2) to the terminal device 104. Inthis example implementation this is done by the target base stationallocating downlink resources to the terminal device by addressingcontrol signaling on a physical downlink control channel, e.g. PDCCH inLTE terminology, to the C-RNTI allocated to the terminal device in thepaging message of step U4 to indicate physical transmission resources ona physical downlink shared channel, e.g. PDSCH in LTE terminology, onwhich the data is to be transmitted. In this regard, the process oftransmitting the data in step U6 may be based on conventional datatransmission schemes in wireless telecommunications networks, albeitwith the terminal device not being in an active RRC connected state andhaving received its temporarily radio network identifier in associationwith a paging message received from the base station (i.e. step U4 inFIG. 5) as opposed to during an RRC connection setup procedure.

It will be appreciated there are various modifications and additionsthat may be made to the processing described above, for example withreference to FIGS. 5 and 6.

For example, in some implementations the core network may be informedthe terminal device is now within the communication cell covered by thetarget base station, so that the target base station should now beconsidered the anchor base station.

In networks in which a common uplink channel similar to PRACH is definedfor the purpose of uplink based mobility, this channel may be utilisedfor the paging response from the terminal device. In this case thepaging response may be received by multiple base stations. This may beone scenario in which it is appropriate for the individual base stationsto indicate in their paging message a characteristic for a terminaldevice to use for the paging response, e.g. a specific preamble, so thata base station can determine if a paging response is transmitted by theterminal device in response to their paging message, or another basestation's paging message. That is to say, the allocation of the pagingpreamble individually by each base station allows the set of basestations in a tracking area to determine which of them the terminaldevice is currently camped on. For example, if a first base stationassigns the terminal device with PREAMBLE_A in its paging message and asecond base station assigns the terminal device with PREAMBLE_B in itspaging message, then if the terminal device transmits PREAMBLE_A in itspaging response, the base stations comprising the radio network candetermine which cell the terminal device is currently camped on (in thisexample, the first base station).

In another embodiment utilising a common PRACH for multiple basestations, the paging preamble that is signaled in steps U3 and U4 ofFIG. 6 may be comprise a “base preamble”, and the preamble that theterminal device uses in its paging response may be a function of thebase preamble and the identity of the base station to which it is campedon. Some examples of this approach include the following:

-   -   The base stations that belong to a RAN notification area        (tracking area) are listed in an RRC message (e.g. received by        the terminal device before it entered the RRC connected inactive        state). The position of the base stations in this notification        area list provides an index of the individual base stations.        When the terminal device receives a paging message, it knows the        base station from which it received that paging message (because        it is camped to that base station) and may thus determine the        index of the base station from which it received the paging        message. In step U5, the terminal device then may then use a        preamble in its paging response corresponding to a combination        of the base preamble received in the paging message and the        index for the base station on which it is camped. Thus, as a        specific example, if the base preamble is preamble number 500,        and the UE determines that it received a paging message from the        base station with index=5 in the RAN notification area, the        terminal device may use preamble number 505 its paging response        in step U5.    -   As a variation of the previous approach, the terminal device may        determine an index of the base station in the RAN notification        area on which it received the paging message and the preamble        that is used in its paging response in step U5 may be a        scrambled version of the base preamble, where the scrambling        sequence is a function of the index.

In another variation of the above-described approach, the pagingmessages of steps U3 and U4 may be transmitted in an SFN (singlefrequency network) area. E.g. all the base stations in the RANnotification area may participate in the SFN. In Step U5, the terminaldevice may send a preamble and this is received by a number of the basestations in the SFN area (e.g. those that are closest to the terminaldevice may typically receive the preamble). The base stations can thencompare, over a backhaul interface, the measurements on the receivedpreamble to determine which base station (or subset of base stations)received the preamble with the greatest signal quality. Thus, when thedata is sent to the terminal device (e.g. in a step corresponding tostep U6), it may be conveyed using a subset of one or more of the basestations associated with the best radio channel conditions for theterminal device, thereby helping to save overall transmission power inthe network and reduce interference.

In one example embodiment, the SFN area may be defined as a subset ofthe RAN notification area. Depending on preference and networkdeployment, different RAN notification areas can be configured, wherethe smallest area may consist of only one cell, and some areas mayconsist of a few cells, and yet some areas may comprise a larger numberof cells, even as large as a whole tracking area. This nature of thisdeployment may be expected to differ between operators, but could alsodiffer within one PLMN or Tracking Area. One aim of a SFN based networkis that the terminal device should receive the same signal from morethan one base-station, but seemingly coming from one base-station viamultipath fading. This implies that the terminal device will likely onlyreceive a transmission from a relatively small number of base-stationsat the same time (transmitting synchronously). Based on this, it may beappropriate for the RAN notification area to be relatively small, forexample smaller than the core network level tracking area and/or it maybe appropriate for a paging strategy to subdivide the RAN notificationarea in smaller SFN based paging areas.

Dividing the RAN notification area into smaller SFN areas may be done ona static or dynamic basis. Thus, a terminal device may move within arelatively large area (the RAN notification area) which is larger thanindividual SFN areas, without being required to informing the networkwhen changing area too often. Networks may configure the sizes of theareas and/or whether a terminal device should inform the network whenmoving out of SFN areas or only when moving outside a RAN notificationarea.

Then when the network needs to reach the terminal device it can decidewhether to page the terminal device in all the different SFN areas moreor less at the same time, or to page the UE in the different SFN areasone by one based on predefined strategy e.g. starting in the SFN area inwhich the UE was last known to be present.

These types of approach could also mean that a preamble that isallocated for a paging response could be associated with an SFN area andnot an individual base station.

In certain embodiments of the disclosure, the paging messages in stepsU3 and/or U4 in FIG. 6 (and the corresponding message at step T2 in FIG.5) may include an indication of the transmit power of the pagingmessage. The terminal device may then use this transmit power in an openloop power control process in order to derive a transmit power for thepreamble. This may be helpful in certain implementations since open looppower control operation is typically based on parameters derived on thePBCH or SYNC channels, but in some scenarios beamforming for thesechannels may be different to the beamforming of the channels used forpaging. This approach thus allows the terminal device to determine atransmit power that is more tailored to the paging process.

In some example implementations, the paging response of step U5 in FIG.6 (and the corresponding message in step T3 in FIG. 5) may include anidentifier for the terminal device to use in association with a messagethat is sent along with the preamble, for example using grant-freeaccess or using contention based uplink resources for use with atwo-step RACH procedure. This can allows the terminal device to transmitsmall amounts of uplink data, e.g. a RRC Connection Request if theterminal device determines that it needs to transition to an active RRCconnected mode.

In some other example implementations, the base station may provide anuplink grant in the paging message to allow the terminal device totransmit data in the uplink, such as an RRC Connection Request orparameters related to resuming a connection. In this regard, the uplinkgrant may be considered a network allocated resource and may be providedin addition to, or instead of, a radio network identifier, such as aC-RNTI, as discussed in the examples above.

The timing of an uplink data transmission will be established relativeto the downlink transmissions, and hence may not be synchronised to theUL (e.g. if the terminal device is located a significant distance fromthe base station). The transmission power for the uplink message may bedetermined by the terminal device by any of several different techniques(e.g. open loop uplink power control, where the UE estimates the pathloss of the downlink transmission and sets the transmit power of theuplink transmission to meet an SIR, signal-to-interference, target).Hence it might in some situations be advantageous for the uplinktransmission to contain a preamble for timing advance and channelestimation purposes. This preamble may, for example, be uniquelyassigned to the terminal device in the uplink grant. The uplink grantmay also indicate the size of the MCS (modulation and coding scheme),frequency and time resources, transport block size (TBS), for themessage.

In accordance with some other example implementations, the base stationmay provide a downlink grant in the paging message to allow the terminaldevice to receive the data on the granted resources. In this regard, thedownlink grant may be considered a network allocated resource and may beprovided in addition to, or instead of, a radio network identifier, suchas a C-RNTI, as discussed in the examples above.

In yet further example implementations, the terminal device location maybe tracked by the network if the terminal device transmits uplinkreference signaling for the network to measure. In this case, the pagingmessage providing the terminal device with an indication of a networkallocated resource would not need to be sent by multiple base stationsin a RAN notification area, but rather because the network already knowsin which cell the terminal is, then it can transmit a single pagingmessage in that cell, and furthermore knows to forward data to thatcell. The “anchor base station” may also be continuously updated as theterminal device moves around the network and this may be signaled backto the core network as appropriate, or alternatively the anchor basestation may be updated only when the paging message needs to be sent(based on the last cell which the network determined to receive the bestuplink signal). In this case, the paging message and paging responsewould not be needed to determine the terminal device location, but maystill be used for the purposes of allocating the network allocatedresource to be used for subsequently communicating data with theterminal device. In this scenario it may be considered helpful in somesituations for the terminal device to monitor for a paging messagefollowing each uplink tracking transmission.

The data exchange signaling in step U6 of FIG. 6 (and in step T4 of FIG.5) may in some implementations also contain timing advance and powercontrol information for the terminal device (corresponding to theinformation currently conveyed in a random access response message in anLTE context). The timing advance and power control information may bebased on measurements by the base station on the paging responsetransmitted by the terminal device. By communicating timing advance andpower control information to the terminal device, the base station canhelp ensure that future uplink transmissions from the terminal deviceare more likely to be appropriately timing advanced/power controlled. Anexample future uplink transmission from the terminal device might beacknowledgment signaling (e.g. ACK/NACK) transmitted on a physicaluplink control channel, PUCCH, relating to the data communicated in stepU6 in FIG. 6 (and the corresponding step T4 in FIG. 5).

In some embodiments, the C-RNTI (or other form of identifier/networkallocated resource) may discarded by the terminal device following thesuccessful exchange of the data. This may be performed, for example,after a predefined timer expiry, after successful transmission of anacknowledgment on the uplink, or following transmission (andacknowledgment) of an uplink response message. In other examples, theC-RNTI (or other network allocated resource) may be stored by the devicefor future communication, until this is overwritten or deleted by thenetwork. In this case, a paging message subsequently received (while theterminal device monitors for signaling address to P-RNTI) will informthe terminal device to start monitoring for control signaling address tothe previously stored C-RNTI (to receive a future downlinkcommunications message).

It will be appreciated that while the above-described exampleimplementations have focused on an example in which the RAN-level pagingnotification area is taken to correspond with the CN-level trackingarea, this is simply for ease of explanation, and in practice the RANnotification area may be a different size, and in particular maycomprise fewer base stations than the core network tracking area.

Furthermore, it will be appreciated that whilst in the above-describedexamples the data is first received at an anchor base station for theterminal device from where it may be communicated to other base stationsin a RAN paging notification area as appropriate, in otherimplementations the data may be initially received, for example from thecore network, at all base stations in a RAN paging notification area.Each base station in the RAN paging notification area may then send apaging message as discussed above, with the base station which receivesa response forwarding on the data. That is to say, in some exampleimplementations there might not be what is referred to above as ananchor base station for the terminal device.

Thus there has been described a method of communicating data between aradio network infrastructure and a terminal device in a wirelesstelecommunications network. The method comprises establishing at a radionetwork infrastructure element there is data available for communicationbetween the radio network infrastructure and the terminal device andtransmitting a paging message for the terminal device from the radionetwork infrastructure element. The paging message comprises anindication of an identifier for the terminal device and an indication ofa network allocated resource for use in subsequently communicating thedata between the radio network infrastructure element and the terminaldevice. In response to receiving the paging message the terminal devicetransmits to the radio network infrastructure element a paging responsemessage indicating the terminal device received the paging message,after which the data is communicated between the radio networkinfrastructure element and the terminal device using the networkallocated resource.

It will be appreciated that while the present disclosure has in somerespects focused on implementations in an LTE-based and/or 5G networkfor the sake of providing specific examples, the same principles can beapplied to other wireless telecommunications systems. Thus, even thoughthe terminology used herein is generally the same or similar to that ofthe LTE and 5G standards, the teachings are not limited to the presentversions of LTE and 5G and could apply equally to any appropriatearrangement not based on LTE or 5G and/or compliant with any otherfuture version of an LTE, 5G or other standard. In particular, whilesome of the specific examples discussed above have been with referenceto a base station as the network infrastructure equipment sponsor forpaging, in other implementations other network infrastructure equipment,for example a TRP in a NR network, may be responsible for this paging.

Further particular and preferred aspects of the present invention areset out in the accompanying independent and dependent claims. It will beappreciated that features of the dependent claims may be combined withfeatures of the independent claims in combinations other than thoseexplicitly set out in the claims.

Thus, the foregoing discussion discloses and describes merely exemplaryembodiments of the present invention. As will be understood by thoseskilled in the art, the present invention may be embodied in otherspecific forms without departing from the spirit or essentialcharacteristics thereof. Accordingly, the disclosure of the presentinvention is intended to be illustrative, but not limiting of the scopeof the invention, as well as other claims. The disclosure, including anyreadily discernible variants of the teachings herein, define, in part,the scope of the foregoing claim terminology such that no inventivesubject matter is dedicated to the public.

Respective features of the present disclosure are defined by thefollowing numbered paragraphs: Paragraph 1. A method of communicatingdata between a radio network infrastructure and a terminal device in awireless telecommunications network, the method comprising: establishingat a radio network infrastructure element there is data available forcommunication between the radio network infrastructure and the terminaldevice; transmitting a paging message for the terminal device from theradio network infrastructure element, wherein the paging messagecomprises an indication of an identifier for the terminal device and anindication of a network allocated resource for use in subsequentlycommunicating the data between the radio network infrastructure elementand the terminal device; and communicating the data between the radionetwork infrastructure element and the terminal device using the networkallocated resource.

Paragraph 2. The method of paragraph 1, further comprising receiving atthe radio network infrastructure element a paging response from theterminal device indicating the terminal device received the pagingmessage transmitted by the radio network infrastructure element.

Paragraph 3. The method of paragraph 1 or 2, wherein the networkallocated resource comprises a network allocated identifier for theterminal device.

Paragraph 4 The method of paragraph 3, wherein the network allocatedidentifier for the terminal device comprises a cell-specific radionetwork temporary identifier, C-RNTI.

Paragraph 5. The method of paragraph 3 or 4, wherein communicating thedata between the radio network infrastructure element and the terminaldevice using the network allocated resource comprises transmitting thedata in association with the network allocated identifier.

Paragraph 6. The method of paragraph 5, wherein transmitting the data inassociation with the network allocated identifier comprises addressingan allocation message comprising an indication of an allocation of radioresources to be used for communicating the data from the radio networkinfrastructure element to the terminal device to the network allocatedidentifier.

Paragraph 7. The method of paragraph 5, wherein transmitting the data inassociation with the network allocated identifier comprises addressingan allocation message comprising an indication of an allocation of radioresources to be used for communicating the data from the terminal deviceto the radio network infrastructure element to the network allocatedidentifier.

Paragraph 8. The method of paragraph 2, wherein communicating the databetween the radio network infrastructure element and the terminal devicecomprises communicating the data from the terminal device to the radionetwork infrastructure element as a part of the paging response.

Paragraph 9. The method of any of paragraphs 1 to 8, wherein the networkallocated resource comprises an allocation of physical transmissionresources to be used for communicating the data between the radionetwork infrastructure element and the terminal device.

Paragraph 10. The method of paragraph 9, wherein allocation of physicaltransmission resources comprise resources on a physical uplink sharedchannel.

Paragraph 11. The method of paragraph 9, wherein allocation of physicaltransmission resources comprise resources on a physical downlink sharedchannel.

Paragraph 12. The method of any of paragraphs 1 to 11, whereinestablishing at the radio network infrastructure element there is dataavailable for communication between the radio network infrastructure andthe terminal device comprises the radio network infrastructure elementreceiving an indication there is data available for communicationbetween the radio network infrastructure and the terminal device from acore network element of the wireless telecommunications network.

Paragraph 13. The method of any of paragraphs 1 to 12, whereinestablishing there is data available for communication between the radionetwork infrastructure and the terminal device comprises the radionetwork infrastructure element receiving an indication there is dataavailable for communication between the radio network infrastructure andthe terminal device from a further radio network infrastructure elementof the wireless telecommunications network.

Paragraph 14. The method of paragraph 13, further comprising the radionetwork infrastructure element conveying to the further radio networkinfrastructure element an indication that it has received the pagingresponse from the terminal device and receiving the data available forcommunication between the radio network infrastructure and the terminaldevice from the further radio network infrastructure element in responsethereto.

Paragraph 15. The method of any of paragraphs 1 to 14, furthercomprising the radio network infrastructure element conveying anindication there is data available for communication between the radionetwork infrastructure and the terminal device to a further radionetwork infrastructure element of the wireless telecommunicationsnetwork.

Paragraph 16. The method of any of paragraphs 1 to 15, wherein thenetwork allocated resource for use in subsequently communicating thedata between the radio network infrastructure element and the terminaldevice is selected from among a plurality of possible network allocatedresources by the radio network infrastructure element.

Paragraph 17. The method of any of paragraphs 1 to 16, wherein anindication of the network allocated resource is received by the radionetwork infrastructure element from a further radio networkinfrastructure element of the wireless telecommunications network.

Paragraph 18. The method of any of paragraphs 1 to 17, wherein thepaging message transmitted by the radio network infrastructure elementcomprises an indication of a characteristic to be used by the terminaldevice for transmitting the paging response to allow the radio networkinfrastructure element to determine the paging response is from theterminal device.

Paragraph 19. The method of paragraph 18, wherein the indication of acharacteristic comprises an indication of a preamble sequence for theterminal device to use for the paging response.

Paragraph 20. The method of any of paragraphs 1 to 19, whereincommunicating the data between the radio network infrastructure elementand the terminal device using the network allocated resource isperformed without the terminal device entering a radio resource control,RRC, connected mode of operation in response to receiving the pagingmessage.

Paragraph 21. The method of any of paragraphs 1 to 20, wherein the stepof communicating the data between the radio network infrastructureelement and the terminal device using the network allocated resourcefurther comprises communicating an indication of a timing advance and/orpower control command for a communication from the terminal device tothe radio network infrastructure element.

Paragraph 22. The method of any of paragraphs 1 to 21, wherein the radionetwork infrastructure element operates in conjunction with a furtherradio network infrastructure element in single frequency network, andwherein the method further comprises: establishing at the further radionetwork infrastructure element there is data available for communicationbetween the radio network infrastructure and the terminal device;transmitting the paging message for the terminal device from the furtherradio network infrastructure element, and communicating the data betweenthe further radio network infrastructure element and the terminal deviceusing the network allocated resource.

Paragraph 23. The method of any of paragraphs 1 to 22, furthercomprising: establishing at a further radio network infrastructureelement there is the data available for communication between the radionetwork infrastructure and the terminal device; transmitting a pagingmessage for the terminal device from the further radio networkinfrastructure element, wherein the paging message comprises anindication of an identifier for the terminal device and an indication ofa further network allocated resource for use in subsequentlycommunicating the data between the further radio network infrastructureelement and the terminal device; determining the terminal device is notwithin a coverage area of the further radio network infrastructureelement; and in response to determining the terminal device is notwithin a coverage area of the further radio network infrastructureelement, not communicating the data between the further radio networkinfrastructure element and the terminal device.

Paragraph 24. A method of operating a radio network infrastructureelement for communicating data between a radio network infrastructureand a terminal device in a wireless telecommunications network, themethod comprising: establishing there is data available forcommunication between the radio network infrastructure and the terminaldevice; transmitting a paging message for the terminal device, whereinthe paging message comprises an indication of an identifier for theterminal device and an indication of a network allocated resource foruse in subsequently communicating the data between the radio networkinfrastructure element and the terminal device; and communicating thedata between the radio network infrastructure element and the terminaldevice using the network allocated resource.

Paragraph 25. A radio network infrastructure element for use incommunicating data between a radio network infrastructure and a terminaldevice in a wireless telecommunications network, wherein the radionetwork infrastructure element comprises controller circuitry andtransceiver circuitry configured to operate together such that the radionetwork infrastructure element is operable to: establish there is dataavailable for communication between the radio network infrastructure andthe terminal device; transmit a paging message for the terminal device,wherein the paging message comprises an indication of an identifier forthe terminal device and an indication of a network allocated resourcefor use in subsequently communicating the data between the radio networkinfrastructure element and the terminal device; and communicate the databetween the radio network infrastructure element and the terminal deviceusing the network allocated resource.

Paragraph 26. Circuitry for a radio network infrastructure element foruse in communicating data between a radio network infrastructure and aterminal device in a wireless telecommunications network, wherein thecircuitry comprises controller circuitry and transceiver circuitryconfigured to operate together such that the circuitry is operable to:establish there is data available for communication between the radionetwork infrastructure and the terminal device; transmit a pagingmessage for the terminal device, wherein the paging message comprises anindication of an identifier for the terminal device and an indication ofa network allocated resource for use in subsequently communicating thedata between the radio network infrastructure element and the terminaldevice; and communicate the data between the radio networkinfrastructure element and the terminal device using the networkallocated resource.

Paragraph 27. A method of operating a terminal device for communicatingdata between a radio network infrastructure and the terminal device in awireless telecommunications network, the method comprising: receiving apaging message from a radio network infrastructure element, wherein thepaging message comprises an indication of an identifier for the terminaldevice and an indication of a network allocated resource for use insubsequently communicating the data between the radio networkinfrastructure element and the terminal device; and communicating thedata between the radio network infrastructure element and the terminaldevice using the network allocated resource.

Paragraph 28. A terminal device for use in communicating data between aradio network infrastructure and the terminal device in a wirelesstelecommunications network, wherein the terminal device comprisescontroller circuitry and transceiver circuitry configured to operatetogether such that the terminal device is operable to: receive a pagingmessage from a radio network infrastructure element, wherein the pagingmessage comprises an indication of an identifier for the terminal deviceand an indication of a network allocated resource for use insubsequently communicating the data between the radio networkinfrastructure element and the terminal device; and communicate the databetween the radio network infrastructure element and the terminal deviceusing the network allocated resource.

Paragraph 29. Circuitry for a terminal device for use in communicatingdata between a radio network infrastructure and the terminal device in awireless telecommunications network, wherein the circuitry comprisescontroller circuitry and transceiver circuitry configured to operatetogether such that the circuitry is operable to: receive a pagingmessage from a radio network infrastructure element, wherein the pagingmessage comprises an indication of an identifier for the terminal deviceand an indication of a network allocated resource for use insubsequently communicating the data between the radio networkinfrastructure element and the terminal device; and communicate the databetween the radio network infrastructure element and the terminal deviceusing the network allocated resource.

REFERENCES

[1] 3GPP document RP-160671, “New SID Proposal: Study on New RadioAccess Technology,” NTT DOCOMO, RAN #71, Gothenburg, Sweden, 7 to 10Mar. 2016

[2] Holma H. and Toskala A, “LTE for UMTS OFDMA and SC-FDMA based radioaccess”, John Wiley and Sons, 2009

[3] ETSI TS 136 321 V13.0.0 (2016 February)/3GPP TS 36.321 version13.0.0 Release 13

[4] “New WI proposal: Signaling reduction to enable light connection forLTE”, 3GPP TSG RAN Meeting #71, RP-160540, Gothenburg, Sweden, 7-10 Mar.2016

[5] “Text Proposal to TR 38.804 on UE states and state transitions forNR”, 3GPP TSG-RAN WG2 #96, R2-168856, R2-168856, 14-18 Nov. 2016

[6] “Evaluation on RAN initiated paging and MME initiated paging”, 3GPPTSG-RAN WG2 Meeting #94, R2-163930, Nanjing, China, 23-27 May 2016

[7] “RAN based Update mechanism for new RAN state”, 3GPP TSG RAN WG2Meeting #96, R2-168525, Reno, USA, 14-18 Nov. 2016

[8] “Discussion on RAN notification area for the new RRC state” 3GPP TSGRAN WG2 Meeting #96, R2-168524, Reno, USA, 14-18 Nov. 2016

[9] “Inactive State principles—RAN based notification area”, 3GPP TSGRAN WG2 Meeting #96, R2-168602, Reno, USA, 14-18 Nov. 2016

1. A method of communicating data between a radio network infrastructureand a terminal device in a wireless telecommunications network, themethod comprising: establishing at a radio network infrastructureelement there is data available for communication between the radionetwork infrastructure and the terminal device; transmitting a pagingmessage for the terminal device from the radio network infrastructureelement, wherein the paging message comprises an indication of anidentifier for the terminal device and an indication of a networkallocated resource for use in subsequently communicating the databetween the radio network infrastructure element and the terminaldevice; and communicating the data between the radio networkinfrastructure element and the terminal device using the networkallocated resource.
 2. The method of claim 1, further comprisingreceiving at the radio network infrastructure element a paging responsefrom the terminal device indicating the terminal device received thepaging message transmitted by the radio network infrastructure element.3. The method of claim 1, wherein the network allocated resourcecomprises a network allocated identifier for the terminal device.
 4. Themethod of claim 3, wherein the network allocated identifier for theterminal device comprises a cell-specific radio network temporaryidentifier, C-RNTI.
 5. The method of claim 3, wherein communicating thedata between the radio network infrastructure element and the terminaldevice using the network allocated resource comprises transmitting thedata in association with the network allocated identifier.
 6. The methodof claim 5, wherein transmitting the data in association with thenetwork allocated identifier comprises addressing an allocation messagecomprising an indication of an allocation of radio resources to be usedfor communicating the data from the radio network infrastructure elementto the terminal device to the network allocated identifier.
 7. Themethod of claim 5, wherein transmitting the data in association with thenetwork allocated identifier comprises addressing an allocation messagecomprising an indication of an allocation of radio resources to be usedfor communicating the data from the terminal device to the radio networkinfrastructure element to the network allocated identifier.
 8. Themethod of claim 2, wherein communicating the data between the radionetwork infrastructure element and the terminal device comprisescommunicating the data from the terminal device to the radio networkinfrastructure element as a part of the paging response.
 9. The methodof claim 1, wherein the network allocated resource comprises anallocation of physical transmission resources to be used forcommunicating the data between the radio network infrastructure elementand the terminal device.
 10. The method of claim 9, wherein allocationof physical transmission resources comprise resources on a physicaluplink shared channel.
 11. The method of claim 9, wherein allocation ofphysical transmission resources comprise resources on a physicaldownlink shared channel.
 12. The method of claim 1, wherein establishingat the radio network infrastructure element there is data available forcommunication between the radio network infrastructure and the terminaldevice comprises the radio network infrastructure element receiving anindication there is data available for communication between the radionetwork infrastructure and the terminal device from a core networkelement of the wireless telecommunications network.
 13. The method ofclaim 1, wherein establishing there is data available for communicationbetween the radio network infrastructure and the terminal devicecomprises the radio network infrastructure element receiving anindication there is data available for communication between the radionetwork infrastructure and the terminal device from a further radionetwork infrastructure element of the wireless telecommunicationsnetwork.
 14. (canceled)
 15. The method of claim 1, further comprisingthe radio network infrastructure element conveying an indication thereis data available for communication between the radio networkinfrastructure and the terminal device to a further radio networkinfrastructure element of the wireless telecommunications network. 16.The method of claim 1, wherein the network allocated resource for use insubsequently communicating the data between the radio networkinfrastructure element and the terminal device is selected from among aplurality of possible network allocated resources by the radio networkinfrastructure element.
 17. The method of claim 1, wherein an indicationof the network allocated resource is received by the radio networkinfrastructure element from a further radio network infrastructureelement of the wireless telecommunications network.
 18. The method ofclaim 1, wherein the paging message transmitted by the radio networkinfrastructure element comprises an indication of a characteristic to beused by the terminal device for transmitting the paging response toallow the radio network infrastructure element to determine the pagingresponse is from the terminal device.
 19. The method of claim 18,wherein the indication of a characteristic comprises an indication of apreamble sequence for the terminal device to use for the pagingresponse. 20-24. (canceled)
 25. A radio network infrastructure elementfor use in communicating data between a radio network infrastructure anda terminal device in a wireless telecommunications network, wherein theradio network infrastructure element comprises controller circuitry andtransceiver circuitry configured to operate together such that the radionetwork infrastructure element is operable to: establish there is dataavailable for communication between the radio network infrastructure andthe terminal device; transmit a paging message for the terminal device,wherein the paging message comprises an indication of an identifier forthe terminal device and an indication of a network allocated resourcefor use in subsequently communicating the data between the radio networkinfrastructure element and the terminal device; and communicate the databetween the radio network infrastructure element and the terminal deviceusing the network allocated resource. 26-27. (canceled)
 28. A terminaldevice for use in communicating data between a radio networkinfrastructure and the terminal device in a wireless telecommunicationsnetwork, wherein the terminal device comprises controller circuitry andtransceiver circuitry configured to operate together such that theterminal device is operable to: receive a paging message from a radionetwork infrastructure element, wherein the paging message comprises anindication of an identifier for the terminal device and an indication ofa network allocated resource for use in subsequently communicating thedata between the radio network infrastructure element and the terminaldevice; and communicate the data between the radio networkinfrastructure element and the terminal device using the networkallocated resource.
 29. (canceled)